Though sales of what are traditionally considered to be computer books continue to be soft, retailers say the technology category is much more solid when you take into account titles that are not related to buying a PC or getting a network to run efficiently, but to activities that happen to require a computer.

"Our market has shifted," says Bill Szabo, buyer and co-owner of Quantum Books, a technical bookstore in Cambridge, Mass. "We're about the same as last year, maybe a little bit up, but we're going away from what would normally be classified as a computer book. If anything, we've gone toward more science books." As with most complex functions these days, those scientific applications—in such fields as engineering or biotech—are done on a computer.

Quantum caters to a highly educated technical community that includes M.I.T. But retailers who serve a more general customer base are similarly finding that some of the healthiest areas lie on the outskirts of computer publishing.

"Over the past year we've seen ever-increasing demand for books about digital photography. In fact, for the first time in Barnes &'s history, "digital photography" became a top-25 search term on our Web site and we expect the sales trend for these titles to continue escalating," says David Rompf, B&N director of merchandising. Among B&'s bestselling tech titles are Real World Camera Raw with Adobe Photoshop (Peachpit Press) and The Photoshop CS Book for Digital Photographers (New Riders).

It's not hard to see what's driving the demand. Sales of digital cameras are booming, with the number sold forecast to rise by 42% this year to 22.8 million—and that follows a 58% increase in 2003, according to industry analysts InfoTrends/CAP Ventures. Compare that to PC sales, which are recovering from a prolonged slump and are forecast to rise only in the low-double digits this year, according to market analyst firm Gartner.

The other big difference is that most of the computers are being purchased by businesses and individuals who are upgrading from their old machines, while the growth in digital camera sales is being driven by first-time buyers who are more likely to need help with the fundamentals.

Digital cameras aren't the only techno-gadgets fueling book sales. MP3 players, in particular the market-leading iPods, are also sending consumers back to the bookstore. "There is quite a range of books about iPods and we expect another lift during the holiday season," says Rompf. That range encompasses titles such as Secrets of the iPod (Peachpit Press), now in its third edition, and Hacking iPods and iTunes (John Wiley), as well as more basic manuals such as iPod and iTunes for Dummies (Wiley) and Absolute Beginner's Guide to iPod and iTunes (Pearson).

The story is the same at rival, says Brooke Gilbert, senior editor for computer and Internet books. "Our inventory has expanded to include titles that assist consumers with various digital products, such as MP3 players and digital cameras," Gilbert says. "Books that cover the iPod and Apple's music application, iTunes, are well-received by customers because these topics usually come packaged together; there are plenty of digital camera help guides that are readily available in a variety of price ranges."

One final computer-related growth area for books isn't a gadget or a program; it's a Web site. "eBay has provided many opportunities for small business sellers and subsequently there is a wealth of titles on the subject," says Gilbert. "In fact, three of the top 25 bestselling titles on our "Digital Business & Culture" bestseller list are books about eBay." At the moment, it seems, one of the best ways to make money from computer books is to help readers make money on their computers.